The Challenge
For RAIN Bottling Company (RAIN), every bottle depends on a tiny part: a rubber gasket. When those gaskets fail, costs spike, and downtime piles up. RAIN relies heavily on “gravity” fillers; these fillers generally run the filling bowl at atmospheric conditions rather than under pressure, as you would see with carbonated products. Gravity fillers are commonly used for bottling water, dairy, syrup, and similar applications. These systems operate by the use of a rubber gasket at the valve nipple to form a seal against the container’s lip (in this case, aluminum bottles). For the filler to work properly, the gaskets must be soft enough to seal completely.
However, RAIN identified an issue early on: the OEM gaskets they were using were both costly and short-lived. They wore out so quickly that replacements were needed on a weekly basis, driving up maintenance costs and downtime.
The recurring problems presented two major challenges. First, the limited wear life of the gaskets meant RAIN’s team was constantly replacing parts, leading to both scheduled and unscheduled downtime. Second, while the OEM’s silicone gaskets provided an effective seal, their softness came at the expense of durability. Bottle lips left deep impressions that ultimately caused tears and rips across the gasket surface.
Overall, RAIN needed a gasket solution that could provide reliable sealing performance without sacrificing durability or driving up costs.
How did the process go?
When RAIN reached out to Will Koepsel, Inside Sales Manager at Specification Rubber Products, Inc. (Spec Rubber), the goal was clear: find a reliable solution to the ongoing gasket issues. RAIN mailed both new and worn OEM gaskets to the Spec Rubber team to evaluate. With the product application in mind, an EPDM NSF-61 material was suggested. It is food safe and provides the right balance – soft enough to compress and seal effectively, yet a considerably longer service life. The Spec Rubber Engineering Team quickly developed prototypes and returned samples for comparison.
One initial obstacle was that Spec Rubber did not stock an OEM-sized replacement gasket. Instead of viewing this as an obstacle, our team approached it as a new product development opportunity.
The Custom Solution
Spec Rubber engineered a custom gasket tailored to match the OEM part in every critical dimension— outside diameter, inside diameter, and thickness. This allowed for a seamless fit for RAIN’s existing gravity fillers.
The real game-changer was the product performance. Spec Rubber was able to increase the durometer of the gasket to 75 +/- 5 Shore A, by using EPDM NSF-61 which is a harder material than the previous OEM gasket. However, the hardness did not compromise the product’s sealing capabilities. By combining the right material with precise customization, RAIN no longer has to choose between performance and longevity.
The Results
Spec Rubber engineered a gasket that proved to be a true drop-in replacement, installing it in just minutes with no adjustments required. Since installation, the gaskets have been outperforming the OEM part without needing a single replacement.
The effect on time and costs has been significant. OEM gaskets were replaced on a weekly schedule, while Spec Rubber’s have been running for more than four months.
Mark Majkrzak, President and Founder of RAIN Bottling Company, highlighted the significance of the gaskets:
“The gaskets made by Spec Rubber have been used in over 10 million cycles. While the initial purchase cost is similar to the OEM’s, to date they have outlasted the OEM parts by at least 10x. We expect the Spec Rubber gaskets to outlast the OEM parts by more than 50x.”
Why it matters
Through collaboration, swift response, and engineering expertise, Spec Rubber delivered a custom gravity filler gasket that has provided superior performance. No matter how big or small, every rubber product that we produce is held to the same high standards to meet and exceed our customers’ expectations every time.
